Sweet, this means my Atlassian-loving company might finally start using a web-based chat room system. For some reason our teams love email, wiki, IMs, but won't even countenance the benefit of realtime chat.
We have a permanent jabber room on our server that all but one dev uses. No one was ever told they needed to be there.
Just start using a chatroom and invite people in. Remind a few to add it to the auto-join list. If your coworkers find a benefit in it, there doesn't need to be an official policy; the usage will just grow organically. If they don't see a benefit, why force it on them?
We used to do this in '99 with an IRC server with all the IT folks on it. We would train the bots with info about systems. You could type an IP - and the bot would reply with the system details, etc.